Senator Edward Kennedy’s diagnosis of a malignant brain tumor is terrible news on multiple levels. While our thoughts go out to the Senator and his family, it’s also difficult to imagine Congress tackling the many important health-related issues before it without Senator Kennedy.

Ezra Klein calls Kennedy “one of the few Senators who is genuinely irreplaceable, whose absence would degrade the nation’s social policy, and thus the life chances and economic security of millions of its disadvantaged residents.”

Mike Lux at Open Left reminds us of the many accomplishments in which Kennedy has been a key player, including the Civil Rights Act of 1964, OSHA, and Family and Medical Leave.

At Gristmill, Kate Sheppard keeps us up to date on the clash between Congress and EPA Administrator Stephen Johnson (over his decision to deny California’s request for a waiver so it could set vehicle emissions standards), while Tom Philpott tracks the ongoing Farm Bill screwups.

Revere at Effect Measure considers the likelihood of EPA doing anything about perchlorate, which contaminates the water supplies of people in 35 states.

Matt Madia at Reg Watch checks in on the Consumer Product Safety Commission, and finds its chief balking at a lead standard and Congress slow on reform efforts.

Rachel Nugent at Global Health Policy outlines some responses to the problem of bad drugs, following a study that found problems with two-thirds of the anti-malarial drugs purchased from pharmacies in six African countries.

Paul Smith at Triple Pundit describes the “Carrot Mob” concept, which uses carrots (increased business) rather than sticks (boycotts) to convince businesses to take positive steps.

Akua at Enviroblog highlights the seven winners this year’s Goldman Environmental Prizes for their work on air pollution in Puerto Rico, deforestation in the Ecuadorian Amazon, sanitation in Mozambique, and other issues.